This invention relates to apparatus and assemblies for article conveying. More particularly, this invention relates to continuous loop belt conveyors.
A continuous loop belt of a common belt conveyor is typically driven and guided by a pair of cylindrical spindles which are spaced apart a distance approximately equal to one-half of the circumferential length of the belt. Such paired conveyor spindles are commonly rotatably mounted upon a support structure comprising parallel side rails, the side rails and cross spanning spindles forming a conveyor frame.
Such common belt conveyor preferably further comprises means for alternately extending and retracting the spindles away from and toward each other, and means for rotating the spindles about their vertical or yaw axes (i.e., axes which are perpendicular to the longitudinal axis of the conveyor, and which are perpendicular to the spindles"" axes of rotation) are preferably provided. By facilitating alternate extension and retraction, such means allows the side rail and spindle assembly to place the continuous loop belt under tension during operation, and allows such continuous loop belt to be alternately released for disassembly and replacement. By facilitating rotation about yaw axes, such means allows the spindles to be angularly positioned for belt tracking, preventing lateral drifting of the belt during operation.
The above described means for spindle extension, retraction, and belt tracking typically comprises rectilinear motion actuators which are connected operably to the conveyor""s side rails and spindles, and which are adapted for selectively altering the effective spindle to spindle length of the conveyor, or adapted for rotating one or both of the spindles about their yaw axes. For purposes of compactness and exterior space economy of such common belt conveyor, the rectilinear motion actuator is known to be mounted within the interior space between the conveyor""s lateral side rails, and between the conveyor""s bed and the lower flight of the conveyor""s closed loop belt. Such positioning of the rectilinear actuators advantageously avoids space consuming upward, downward, or laterally outward structural protrusions. However, various assemblies associated with belt conveyors are known to be advantageously mounted within the interior space between the conveyor""s side rails, bed and lower belt flight. For example, where the belt conveyor is adapted for air cushioned or vacuum assisted conveying, air ducts and plenums commonly occupy such space. As another example, magnet assemblies are commonly mounted within such space for prevention of slippage of ferrous articles carried by the belt. As a further example, heating apparatus may be advantageously installed within such interior space for application of heat to conveyed articles.
Where the above described rectilinear motion actuators protrude into or occupy portions of the interior space between the conveyor""s side rails, bed, and lower belt flight, the actuators tend to undesirably interfere with or prevent such other advantageous known uses of such space.
The instant inventive conveyor side rail solves or ameliorates the conveyor space usage problems described above by positioning and mounting rectilinear motion actuating rack and pinion assembly in a manner promoting exterior space economy of the conveyor, avoiding any significant upward, downwardly, and outward structural protrusion, and in a manner preventing such assembly from occupying the interior space between the conveyor""s side rails, bed, and lower belt flight.
The instant inventive conveyor side rail comprises first and second side rail sections, the first side rail section necessarily having a hollow interior space adapted for receiving and operatively supporting a rack and pinion assembly. The pinion of the rack and pinion assembly preferably has oppositely and axially extending journals which are nestingly received by annular bearings which are housed and supported within the first side rail section""s hollow interior space. Preferably, the lateral side wall surfaces of such space are molded or milled to include such annular bearings. Also preferably, the pinion is rotatably supported within the hollow space so that the pinion""s axis of rotation is substantially perpendicular to the lateral sides of the first side rail section.
Necessarily, the first side rail section""s hollow interior space has a first lateral opening, such opening facilitating application of rotational torque to the pinion. The first lateral opening is preferably configured circularly and is closely fitted to the outside diameter of one of the pinion""s journals, such configuration allowing the first lateral opening to dually function for pinion rotating access, and as an annular bearing.
The side of the pinion which is exposed to the first lateral opening preferably comprises rotating means, preferably comprising an axially aligned non-circular aperture. Suitably, such aperture is hexagonally shaped for nesting receipt of an allen head wrench. Suitably, such laterally exposed side of the pinion may alternately comprise an outwardly protruding prismatic lug for application of rotating torque via a common socket wrench.
The hollow interior space between the lateral sides of the first side rail section preferably further comprises a longitudinally extending chamber fitted for sliding receipt of a rack, such longitudinal chamber being positioned to facilitate operative engagement of the teeth of the rack with the teeth of the pinion. Necessarily, the longitudinal chamber extends to and opens at one of the longitudinal ends of the first side rail section.
Preferably, the first side rail section""s hollow interior space further opens oppositely from the above described first lateral opening, such opposite opening providing access to the pinion and rack chambers of the hollow interior space for assembly, disassembly, and maintenance of the rack and pinion assembly. A rack and pinion retaining plate preferably covers such opposite or second lateral opening, such plate preferably being removably attached by means of screws. Like the opposite lateral wall of the hollow interior space, the rack and pinion retaining plate preferably presents annular bearing surfaces for nesting receipt and rotatable support of the pinion.
In operation of the above described preferred embodiment of the first side rail section, the driving head of an allen wrench is inserted into the pinion""s hexagonal aperture via the hollow interior space""s first lateral opening. Thereafter, the allen wrench may be alternately rotated and counter rotated, applying rotational torque to the pinion, and causing the pinion to rotate and counter rotate against the rack, alternately extending and retracting an end of the rack from and into the hollow interior space""s longitudinal opening.
The instant inventive conveyor side rail necessarily further comprises a second side rail section and telescoping means which is adapted for interconnecting the first and second side rail sections, such means being further adapted for aligning the first and second side rail sections so that the longitudinal opening of the first side rail section""s hollow interior space faces a longitudinal end of the second side rail section, and such means being further adapted for facilitating longitudinal telescoping motions of the first and second side rail sections toward and away from each other. According to the functions of the telescoping means, upon operation of the rack and pinion assembly to extend the rack, an end of the rack contacts the longitudinal end of the second side rail section, telescopingly extending the first side rail section away from the second side rail section. Opposite operation of the rack and pinion assembly to retract the rack, frees the first and second side rail sections for telescoping retraction toward each other.
Preferably, the telescoping means comprises an arm extending longitudinally from the first or second side rail sections, such arm supporting a longitudinally extending slide ridge, the slide ridge being nestingly and slidably received by a slide channel within the first or second side rail section. Where the longitudinally extending arm extends from one of the sections among the first and second side rail sections, the other section necessarily includes the slide channel which nestingly receives the slide ridge. When such arm alternately includes a slide channel, such other section necessarily supports the slide ridge. Suitably, the telescoping means may alternately comprise a slide shaft and slide channel assembly, or may comprise a slide slot and slide pin assembly.
Releasable locking means further interconnecting the first and second side rail sections are necessarily provided, such means being adapted for selectively and alternately fixing the first and second side rail sections in an extended position with respect to each other for maintenance of belt tension, and adapted for releasing the first and second side rail sections for retracting motion toward each other, slackening the belt and allowing disassembly and replacement of the belt. Preferably, the releasable locking means comprises a xe2x80x9cTxe2x80x9d nut clamp and xe2x80x9cTxe2x80x9d channel assembly, such assembly dually functioning as the above described telescoping means. Suitably, the releasable locking means may alternately comprise a clamping means selected from numerous other commonly known releasable clamping means such as a xe2x80x9cCxe2x80x9d clamps and set screw and slide bar assemblies. For quick release and clamping, levered cam locks may serve as a suitable substitute for screw actuated clamps.
The opposite longitudinal end of the first side tail section (i.e., the end which is opposite the longitudinal end which includes the hollow space""s longitudinal opening) is preferably configured to include conveyor spindle mounting means, such means preferably comprising a spindle axle or a spindle axle receiving aperture. Said opposite longitudinal end may be suitably alternately configured to include means for mounting and longitudinally aligning a third conveyor side rail section. Suitably, the spindle mounting means may be alternately carried by the distal or opposite longitudinal end of the second side rail section, or by the distal or opposite end of such third side rail section.
In practice, a pair of the instant inventive conveyor side rails are preferably incorporated within a belt conveyor, the pair serving as a major structural components of the belt conveyor""s frame. The inventive side rails allow the overall effective length of the conveyor to be alternately lengthened and shortened for alternate belt tensioning and belt releasing. Where a longitudinal end of at least one of such pair of inventive conveyor side rails comprises spindle mounting means, as described above, such at least one side rail may be individually manipulated for belt tracking adjustment.
Accordingly, an object of the instant invention is to provide a conveyor side rail capable of alternate lengthening and shortening through the action of a compactly mounted rectilinear motion actuator.
It is a further object of the present invention to provide such a conveyor side rail which promotes both exterior and interior space economy, and whose rectilinear motion actuator comprises a rack and pinion assembly occupying a hollow interior space within the side rail.
Other and further objects, benefits, and advantages of the present invention will become known to those skilled in the art upon review of the Detailed Description which follows, and upon review of the appended drawings.